The idea of exploring familiar characters in alternate realities has become a staple of storytelling. This is especially true in comic books, where characters must constantly be updated and often re-defined for new eras and generations.

The medium of comics naturally lends itself to presenting “what if” stories that shed new light on the characters without subjecting them to situations that would hinder or alter their ongoing storylines. Decades ago, they were called “imaginary stories.” In 1989, DC Comics started calling them “Elseworlds.”

The first of the Elseworlds brand was that year’s Gotham by Gaslight, which re-imagined Batman as a vigilante detective at the turn of the 19th century confronting Jack the Ripper. That was the conceit of Elseworlds: to put superheroes and their supporting cast in alternate timelines, either by exploring them in different eras, or changing something in their own personal history to create a ripple effect (a later story that often gets mentioned for potential adaptation found Superman raised as a hero of the Soviet Union).

The latest entry of the animated DC Universe is loosely based on the Gotham by Gaslight on-shot graphic novel, while also drawing heavily upon its sequel, 1991’s Master of the Future. In deconstructing the original story, the filmmakers have given the concept a new life, presenting a satisfying mystery that plays out quite differently from the book. This lets the film stand quite well as its own thing while honoring the spirit of the books, allowing longtime fans to watch without any fear of spoilers.

The animation is distinctive and beautiful, and the screenplay is filled with fun nods to Batman lore that fans should appreciate.

The Blu-ray includes a 20-minute featurette about the original graphic novel, as well as a nice audio commentary from the filmmakers. Both delve into just why Gotham by Gaslight has become an iconic Batman story.

The Blu-ray also includes an eight-and-a-half-minute preview of the next DC Universe animated movie, Suicide Squad: Hell to Pay, plus some bonus cartoons from animated Batman TV shows.

Warner Bros. Home Entertainment held the premiere for the new animated film Batman: Gotham by Gaslight Feb. 5 at The Paley Center for Media in Beverly Hills, Calif. The film, a re-imagining of Batman as a detective chasing Jack the Ripper, was released on Blu-ray, DVD and 4K Ultra HD Blu-ray Feb. 6.